:root {
  /*声明一个变量*/
  --scroll-color: #0000;
  --bubble-float: left;
  --bubble-left: 19px;
  --bubble-right: 0;
}

body {
  overflow: hidden;
  background-size: cover;
  background-image: url("../img/bg.jpg");
}

.main {
  width: 1080px;
  height: 648px;
  margin-top: 72px;
  margin-left: auto;
  margin-right: auto;
  border-radius: 5px;
  border: #d0d0d0 1px solid;
  background-color: #fff;
  box-shadow: 0 2px 4px rgba(0, 0, 0, .12), 0 0 6px rgba(0, 0, 0, .04)
}

.contact {
  width: 360px;
  height: 100%;
  float: left;
  border-right: #d0d0d0 1px solid;
}

.contact .top {
  width: 100%;
  height: 80px;
  display: flex;
  align-items: center;
  border-bottom: #e0dfdf 1px solid;
}

.contact .top .left {
  flex: 1;
  text-align: center;
}

.avatar {
  width: 48px;
  height: 48px;
  border-radius: 24px;
}

.contact .top .right {
  flex: 3;
}

.dialog {
  width: 719px;
  height: 100%;
  float: right;
}

.dialog .top {
  width: 100%;
  height: 60px;
  font-size: 24px;
  line-height: 60px;
  text-align: center;
  border-bottom: #d0d0d0 1px solid;
}

.dialog .top::after {
  content: " ";
  float: right;
  position: relative;
  top: 61px;
  border: 4px solid #0000;
  border-top-color: #8e9292;
}

.dialog .middle {
  height: 432px;
  overflow: auto;
  padding: 10px;
  margin: 6px 0 11px 0;
}

.dialog .middle::-webkit-scrollbar {
  /*设置滚动条的宽度*/
  width: 8px;
}

.dialog .middle::-webkit-scrollbar-thumb {
  /*设置滚动条圆角*/
  border-radius: 4px;
  /*设置滚动条颜色, 颜色上述声明的变量值*/
  background-color: var(--scroll-color);
}

.dialog .middle::-webkit-scrollbar-track {
  /*设置轨道颜色, 与背景色相同, 以便隐藏*/
  background: #fff;
}

.dialog .msg, .msg-right {
  height: 60px;
  border: #51a5e6 1px solid;
  border-radius: 3px;
  margin-bottom: 10px;
  padding: 10px;
}

.dialog .msg::after, .msg-right::after {
  content: " ";
  float: left;
  position: relative;
  left: -19px;
  border: 4px solid #0000;
  border-right-color: #83b7e0;
}

.msg-right::after {
  right: -19px;
  left: initial;
  float: right !important;
  border-right-color: #0000;
  border-left-color: #83b7e0;
}

.dialog .line {
  width: 100%;
  height: 0;
  position: relative;
  top: -6px;
  border-top: #d0d0d0 1px solid;
}

.dialog .bottom {
  padding-left: 10px;
  padding-right: 25px;
}

.messageText {
  position: relative;
  margin-right: 2px;
  font: 14px/1.5 Helvetica,Arial,Tahoma,微软雅黑;
  width: 100%;
  height: 106px;
  outline: none;
  background: #fff;
  border: 0 none;
  overflow-y: auto;
  -webkit-box-sizing: border-box;
  box-sizing: border-box;
  resize: none;
  vertical-align: middle;
  display: inline-block;
}

.dialog .bottom::after {
  content: " ";
  float: right;
  position: relative;
  top: -121px;
  left: 75px;
  border: 4px solid #0000;
  border-bottom-color: #8e9292;
}

.send {
  float: right;
  position: relative;
  top: -20px;
  left: 10px;
  background-color: #51a5e6;
  border: #87ceeb;
  color: #fff;
  font-size: 12px;
  width: 50px;
  height: 22px;
  border-radius: 3px;
}

.send:focus{
  outline: none;
}
